Cheap and very good - little pig oil and water on a cloth.
Alva dazzle - best on the market and Asorbine is my second choice.
I do love Supreme's Sparkle for mane and tails but wash out afterwards as I avoid silcon products apart from when showing as silcon is not good for hair.
Fly Away make one, but I can't remember the name, it comes in a purple can, much better than any other I have ever tried. I haven't used one for ages though because my boy just SHINES naturally.